It is not to be confused with "combining minus below" ̠ (U+0320), "combining low line" ̲̲ (U+0332) and "low line" ("underscore") _ ). The difference between "macron below" and "low line" is that the latter will result in an unbroken underline when run together, compare a̱ḇc̱ vs. a̲b̲c̲ (of which only the latter should look like abc).

Note that the Unicode names of composed characters whose decompositions contain this character misleadingly have "line below" rather than "macron below". Thus, ḇ "Latin small letter b with line below" decomposes to "Latin small letter b" and "combining macron below".

Ḇ (minuscule: ḇ) is used, for example, in the transliteration of Biblical Hebrew into the Roman alphabet to show the fricative value of the letter beth (ב). representing [v], or perhaps [β]. In Unicode the capital Ḇ is codepoint U+1E06 (7686) and the lower case ḇ is U+1E07 (7687).